1. Field of the Invention
The present invention generally relates to data processing systems and more particularly relates to apparatus and methods for efficient reconfiguration of extremely large scale data processing systems within the field.
2. Description of the Prior Art
It is known in the art to construct and operate extremely large scale digital data processing systems. Historically, these were known as “main frame” computers wherein the primary digital data processing hardware consisted of electronic components installed into one or more steel frames which occupied a large volume within the users computer center.
As main frame computers became larger, more capable, and more expensive, manufacturers tended to make them modular in nature. The first modules were hardware. Thus, users could purchase and utilize additional memory modules, peripherals devices, instruction processors, etc. to accommodate increasing data processing demands.
In similar fashion, system component suppliers began to provide software in modular form as well. Modular software enables the user to purchase and utilize only such software capabilities as are required within a particular installation. As needs change, other software modules may be added to enhance available capabilities. However, to install an additional software module, early systems required all software to be reloaded. This reloading process was often called a system generation or “sysgen”. This process was necessary to link all previous and newly added software modules to one another and to allocate available memory to all previous and newly added software modules. The primary disadvantage is the processing time lost during the complete reload of the system, because the system needed to be rendered completely inoperative during sysgen. As the systems become more complex and contain more software modules, the sysgen process takes just that much longer. Furthermore, certain individual modules may require the loading of patches to fix known software bugs. This exacerbates the problem by taking even longer.
Much more recently, repeating the sysgen process for software module additions has become just too costly. Because memory storage space is now much less expensive, it is typical to load virtually all available software into a system even though only a portion of that software is to be utilized. The user purchases a “key” to enable access to each of the software modules which are needed. The key is a small file which enables access to the corresponding software module. Whenever an additional capability is desired, the user purchases a key for the new software module to be activated within the system. In practice this involves the sending of a storage device (e.g., CD-ROM) containing the desired key via mail or courier to the user after payment is assured.